1. Field of the Invention
The present invention relates to an actuator for lifting a hood of a motor vehicle, particularly relates to a one-way locking mechanism of the actuator.
2. Description of the Related Art
A mechanism for lifting a hood of a motor vehicle has been proposed to absorb collision energy when an obstacle collides with the hood. The mechanism lifts the back end of the hood with the front end of the vehicle as a fulcrum to provide a space behind the hood in the event of the collision. When the obstacle collides with the hood, the hood can deform downward so as to improve the absorption amount of the collision energy by the deformation of the hood.
Such a mechanism for lifting a hood is disclosed in Japanese Unexamined Patent Application Publication No. 2004-203379 (hereafter referred to Nadeau et al, equivalent to U.S. Patent Application Publication No. 2004/0134705 A1), for example, which is hereby incorporated by reference. According to Nadeau et al., a hood (bonnet) is engaged with a body of a vehicle rotatably around a rotation axis at a rear part of the hood. In a normal operation, the hood rotates about a vehicle body to open. In the event of a collision, an actuator lifts a link rod engaged with the rotation axis so that the rear part of the hood is lifted. In the actuator, an explosive power of gunpowder and the like makes the rod protrude from a cylinder to generate the actuator force.